In recent years, as a portable phone, a digital AV device, an IC card and the like have been sophisticated, there is a growing demand for reduction in size and thickness of a semiconductor silicon chip to be mounted (hereinafter, referred to as ‘chip’), so as to highly integrate the chips in a package. For example, in an integrated circuit in which a plurality of chips is constituted into a one packaging structure, as typified by a CSP (chip size package) or MCP (multi-chip package), the further thinning is required. In order to implement the high integration of the chips in the package, it is required to thin a thickness of the chip to a range of 25 to 150 μm.
However, since a semiconductor wafer (hereinafter, referred to as ‘wafer’), which is a base of the chip, is thinned by the grinding, the strength thereof is weakened, so that a crack or bending is likely to occur. Also, since it is difficult to automatically convey the wafer of which strength is weakened due to the reduction in the thickness, the wafer should be conveyed by a person's hand, which makes the handling troublesome.
For this reason, a wafer handling system has been developed which is configured to attach a plate made of glass, silicon or rigid plastic and referred to as a support plate to a wafer to be ground, thereby holding strength of the wafer and preventing occurrence of a crack and bending of the wafer. Since it is possible to keep the strength of the wafer by the wafer handling system, it is possible to implement the automatic conveyance of the thinned wafer.
In the wafer handling system, the wafer and the support plate are attached to each other using an adhesive layer formed by an adhesive tape, a thermoplastic resin, an adhesive and the like.
Regarding an attaching device and an attaching method for performing the attaching, Patent Document 1 discloses an attaching device and an attaching method, in which a placement plate on which a substrate is placed, a press plate configured to press a support plate to the substrate and a pair of alignment members capable of advancing and retreating in a horizontal direction are provided, and a tip portion of the alignment member is provided with a blade configured to support a lower surface of a peripheral edge portion of the support plate and a pressing member configured to perform a positioning operation with the support plate being overlapped over the substrate. Also, Patent Document 2 discloses a superimposing unit and an attaching device in which a support unit configured to support a wafer or support plate and a conveying unit configured to convey the wafer or support plate are provided, and the support unit has three or more columnar members having a first support part configured to support an end portion of the wafer or support plate and a first positioning part configured to guide the end portion to the first support part.